Gauging apparatus for controlling a grinding operation



BLESSING GAUGING APPARATUS FOR CONTROLLINGl Aug. 24, 194s.

Filgd June 2a, 194s` A GRINDING OPERATION v 2 Sheets-Sheet 1 i Aug. 2%, w48'. I w. H. BLEsslNG 4479553 GAUGING APPARATUS FOR CONTROLLING A GRINDING OPERATION Filed June 28,' 1945 2 sheets-sheet 2 HIS A TTORJVEY Patented Aug. 24, 1948 GAUGING APPARATUS FOR CONTROLLING A GRINDING OPERATION William H. Blessing, Meriden, Conn., assigner to General Motors Cor poration, Detroit, Mich., a corporation of Delaware Application June 28,1945, serial No. 602,115

26 Claims. l

This invention relates to gauging apparatus and particularly to gauging apparatus which controls a sizing operation on a work piece,

An object of the invention is to provide an improved gauging apparatus for controlling a grinding operation on one of a pair of articles to be used in mating relation, and wherein the size of one of the articles already nished controls the grinding to size of the other article.

Another object is to provide improved gauging apparatus for controlling the grinding of a work piece to a size determined by the measured size of another work piece.

To these ends and also to improve generally upon devices of the character indicated, the invention consists in the various matters hereinafter decribed and claimed. In its broader aspects,

the invention is not necessarily limited to the specic construction selected for illustrative purposes in the accompanying drawings wherein Figure l is a diagrammatic fragmentary showing of the matched grinding control mechanism with the parts in position to eiect a finish grinding operation;

Figure 2 is a front elevation of the feeding mechanism with the feeding pawls in positions to produce a finish grinding feed;

Figure 3 is a vertical section taken approximately along the line 3 3 of Figure 1;

Figure 4 vis an enlarged perspective view of the valve operating members within the gauging mechanism;

Figure 5 is a fragmentary sectional View along the lines 5-5 of Figure 1;

Figure 6 is a fragmentary sectional view taken along the lines 6- of Figure 4;

Figure 7 is anenlarged sectional view showing a portion of one of the feeding control valves; and

Figure 8 is an enlarged fragmentary Vview of the mechanism for lifting the gauging stem.

This invention, which controls the grinding of one article to a size determined by the measured size of another article, is particularly adapted for controlling a grinding operation upon a raceway on one of a pair of race rings to be used in mating relation in an antifrictlon bearing. The raceway grooves for the mating race rings of ball bearings are ordinarly ground separately on oscillating grinding machines, these raceways being ground to predetermined sizes within as close limits of accuracy as the grinding machines are capable. Rolling elements of a given size are then interposed between the race rings. Due to slight inaccuracies of grinding, either one or both racetaken the mating raceways.

2 way grooves may be oversize or may be undersize, and frequently these errors of grinding are cumulative. Attempts t-o reduce these cumulative errors have been made vby gauging and matching the raceway sizes of the mating race rings so that the errors would tend to compensate each other. Also, some of these errors have been reduced by selecting the sizes of the balls which roll within The additional operations of gauging and sorting race rings and balls for matching relation hinders production and often results in incorrect nt of balls within the raceways. According to the present invention, the raceways of either the outer or the inner race rings are ground in a satisfactory manner and as closely as possible to the desired finished raceway size. Thereafter, each finished raceway, irrespective of its size, is used in conjunction with my gauging apparatus to control the grinding to a corresponding size of the raceway to be used therewith in mating relation. By way of illustration, the invention is herein described by reference to the grinding of the raceway of a ball 'bearing inner race ring under control of the finished raceway size of the outer race ring that is to -be used in mating relating with this inner race ring.

Generally considered, an outer race ring, as A, has a finished raceway B measured by a gauge l0 provided with a, valve lever l2 whosevposition is determined by the size of the raceway B. An inner race ring, as C, provided with a raceway R to be ground by a grinding wheel lll to a size for assembly in mating relation through standard sized bearing balls with theraceway B, is rotatably mounted in a suitable manner for grinding, as on an oscillating grinding machine. The details of this grindingmachine are not herein illustrated since they may be variously consituted in accordance with standard construction. During grinding, a gauging mechanism, :generally indicated at l5, has a vertically movable stem I6 that responds to the size of the raceway R and acts through an amplifying leverage and a pivoted transfer lever i8 to successively open a pair of self-closing ap valves 20 and 2l on the valve lever l2, these valves being respectively connected through ducts or hoses 22 and 23 to a, pair of grinding feed controlling valves 24 and 25. A suction pump P produces a partial vacuum or less than atmospheric pressure in the hoses when the flap valves are closed. When the raceway R is ground down nearly to the nal size determined by the position of ,the valve lever I2, an adjusting f screw 21 on the advancing lever lll opens the iiap tightened against the valve which admits atmospheric pressure into the hose 22 causing the feeding control valve 24 to change an initial coarse .grinding feed to a finish grinding feed. When` the raceway R is completely ground except for sparking outl a stud 23 (Figure 4) on the advancing arm I3 opens the flap valve 2l which admits atmospheric pressure into the hose 23 causing the valve 25 to stop the grinding wheel feed. At the completion of the grinding operation, the grinding machine is stopped and the stem I3 is lifted out of raceway engagement causing both flap valves to close. The suction pump P again produces a partial vacuum in the hoses 22 4and 231 and returns the valves 24 and 25 to their initial positions which will cause a coarse feed of the grinding wheel at the start of the next grinding cycle.

In the illustrated embodiment, the gauging mechanism i0, which may be suitably supported in a fixed position above the race ring C during grinding, is provided with a ball-type gauge for supporting and gauging the outer race ring A which determines the grinding to size of the raceway R. A horizontally disposed sleeve 32 axially extends through a supporting bracket 33, fastened to a side of a casing 34, and into an aperture through this casing. The sleeve 32 is slidably journalled in the ends of the bracket 33 and is threaded in this bracket at 35 for axial adjustment. The outer end of the sleeve 32 terminates in a truste-conical head 36 which engages a series of peripherally spaced balls 31 loosely held within and extending through ball pockets 3B formed by a flanged annular member 43 and a cylindricaLhead 42. These balls preferably are the same size as and are spacedI correspondingly to the balls which will be later assembled with the race rings A and C. The flanged annular member 4l loosely surrounds the sleeve 32, and the ball pockets have plates provided with flat wear-resistant ball engaging faces 43 located in a common plane perpendicular to the axis of the frustoconical head 36. A rod 44, coaxial with the head 33, axially extends through and is journalled in the sleeve 32. A coiled spring 45, compressed between an end of the sleeve 32 and a collar 46 fastened on the rod 44, yieldably urges this rod into the easing to a gauging position which is determined by that axial position of this rod at which the ball engaging faces 43 uniformly urge the balls 31 upwardly on the frusto-conical head 3l and. into seated engagement with the raceway B. To prevent uneven wear of the head 36 and to assure that the rod 44 is located in gauging position, the race ring A may be manually turned on the supporting balls 31,

The valve lever I2. which is pivotally supported by a pair of spring reeds 41 mounted in a block secured to the casing, is shifted by the rounded end of the rod 44 to a gauging position determined by the size of the raceway B. A spanner ring 43, fastened to the sleeve 32, has peripheral graduations adjacent to an index finger on the supporting member 33 as shown in Figure 5. Rotatingl this spanner ring axially positions the sleeve 32 and the rod 44 to control the operating lever 53 acts through a shaft 54, projecting through a casing cover 55 and journalled in a casing braeketj, to swing a forked depending arm of a lever 61 against the collar 46 to retract the rod 44 from gauging position which permits the balls 31 to shift laterally and radially inwardly with respect to the frusta-conical head 36 so that the race ring A may be mounted 'in and demounted from gauging position. An adjustable stop screw 53, extending through the upper end of the lever 51, is engageable with the bracket 53 to prevent the lever 51 from moving into interfering relation with the valve lever I2. The casing cover 55 has a window 59 through which the operator may observe the operating positions of valves 20 and 2l. A lter B0 mounted in a bore through the casing cover 55 admits air to the valves 20 and 2 l. l

The stem I8 is vertically slidable in a boss 6i at the bottom of the casing 34 and in a bushing B2 having a lower reduced portion pressed within a boss 63 secured to the top of the casing. A suitably hard gauging point B4, as a diamond, projecting from the lower end of the stem I6. rides u'pon the raceway R. and supports the stem i6 during grinding. A coiled spring 65, compressed between the top of the casing and a collar on the stern I6, yieldably urges the stem i6 downwardly into gauging position. A collar 66, journailed on the enlarged upper portion of the bushing 62 (Figure 8) and normally seated on the top of the boss 63 has a spiral slot 61 open at its lower end and slidably engaging a pin 38 laterally projecting from the enlarged upper end of the l non-rotatable bushing 62.' AA washer 10, loosely fitted over the upper end of the bushing 62, is normally loosely positioned between the top of the collar 66 and the underside of a cup-shaped cover 12 secured by a cap nut against a shoulder on the positions of the valves 23 and 2| with respect to the measured size of the raceway B. The spanner ring 4I is preferably s0 graduated that rotating of this ring from one graduation to the next effects a change of one ten thousandth of an inch in the size to which the raceway R is ground. A locknut I2, threaded upon the sleeve 32, may be supporting member 33 to secure this sleeve in adjusted position. A hand upper end of the stem I6. A hand lever 13, projecting through a slot 14 in the cover 12, is threaded into the collar 66, When this hand lever is swung to the position of Figures l and 8 to locate the pin 68 at the top of its slot 61, the stem IB is lowered into supported relation upon the raceway R, and there is sufficient clearance between the top of the washer 10 and the underside of the cover12 so that the stem i6 is free to move downwardly and remains supported by the raceway R during the entire grinding operation. During gauging, the hand lever 13 may be secured in position by a spring 15 mounted on the cover 12 When this hand lever is swung to. the opposite end of the slot 14, the collar 66 rides upwardly on the pin 38 and acts through the washer 10 and the cover 12 to lift the stem I6 out of raceway engagement so that a race ring C may be mounted in and demounted from grinding position. To secure the stem I6 in its inoperative raised position, the hand lever 13 is swung sufficiently to remove the pin 38 from the open lower end of the slot 61 and the bottom of the collar 68 is supported by this pin.

A block 16. fastened to a. lower portion of the casing 34, holds an end of each of a pair of spaced generally horizontal reed springs 11 whose other ends co-operatively support a, vertically floating block 18. A block 19, fastened to the stem I6, has Aon its lower end a hardened contact point engaged by a laterally projecting arm 8l on the floating block 18 which is urged upwardly by a coiled spring r82 causing the floating block 18 to assume a vertical position dependent upon the vertical'position of the stem I6. A pair of upwardly extending flat springs B3 and 84, whose -movement of the spring spaced lower ends are secured respectively to the upper ends of the blocks 16 and '|8, are secured intermediate of their lengths to a spacer plate 05 and are also secured together at their upper ends. The downward movement of the stem I6 and of the floating block 18 in response to a reduction in size of the raceway R, produces a corresponding downward movement of the spring 84 while the fixed block 'I6 prevents a bodily downward movement of the spring 83. These springs coact as an amplifying lever wherein a slight downward 84 results in a greatly amplified movement of the upper ends of both springs towards the valve lever I2. An upward movement of the stem I6 out of raceway engagement produces an amplified swinging movement of the upper ends of both springs 83. v04 away from the valve lever |2 and to a stop position limited by an adjustable screw'86 threaded in the casing 34. The transfer lever I0, which is generally T-shaped with a transversely extending head 81, is pivotally supported at its lower end by a cross shaft 88, and a counterweight lever portion 90 urges this lever clockwise to a position determined by the engagement of one end of the head 81 against a stud 92 which laterally projects from the upper ends of both springs 83 and 84.

The self-closing flap valves and 2|, which control the operation of the grinding wheel feeding control valves 24 and 25, include a pair of spaced upwardly extending spring flaps 03 and 94 whose lower ends are rigidly fastened to the valve lever I2 and whose upper ends are arranged to be engaged respectively by the adjusting screw 2l to open the valve 20 for changing an initial coarse grinding wheel feed to a finish grinding feed, and by the stud 28 to open the valve 2| for stopping and grinding wheel feed when the raceway R is ground down to a size determined by the measured size 4of the raceway B. The .subsequent sparking-out of the grinding wheel brings the raceway R to a final size for mating relation with the race ring A when assembled with standard sized balls; The spring flaps 93 and 94 tend to close ports 95 and 9B at the ends of valve chambers 91 and 98 to which are connected the hoses 22 and 23, these hoses having suilicient flexibility to permit positioning of the valve lever I2 by the rod 44 The grinding wheel feeding mechanism vincludes a ratchet wheel |00 suitably arranged to operate a screw shaft for producing a feed of the grinding wheel I4. Pawls |02 and |03, pivotally secured at their rearward ends to an oscillating lever |04, are urged by a coiled spring |03 towards ratchet wheel engagement. The oscillating lever |04 is pivotally supported by a screw |06 carried by a frame |01, and is oscillated through an adjustable extent by a link |08 whose lower end is journalled upon a crank pin ||0 having its throw adjusted by a screw i I2. The vcrank pin ||0 may be revolved by a motor or other suitable driving mechanism. Pivoted to the frame |07 at H3 is a lever I4 provided with a cam portion H5 engageable with a screw ||6 adjustably threaded through a plate I which is fastened to and longitudinally adjustable on the pawl 02. The lever I|4 also has a cam portion ||8 engageable with a screw |20 adjustably threaded through a plate I 22 which is secured to and longitudinally adjustable on the pawl |03. A coiled spring |24, connected to the lower end of the lever I4, urges this lever clockwise towards engagement with an adjustable stop screw |26. Latch blocks |21 and 28, laterally projecting from the lower end of spring urged towards ratchet tooth the lever I|4, are respectively engageable with a latch pin |30 to initially locate the lever ||4 at position |I4A'wherein both pawlsfIilZ and |03 cooperatively produce the initial coarse grinding wheel feed, and with a latch pin I3| to subsequently locate this lever ||4 at its full line indicated position wherein the cam portions ||5 and ||8 will limit the effective feeding strokes of the pawls |02 and |03 to provide a finishing feed of the grinding wheel I4. When the latch pin |3| is thereafter withdrawn from engagement with the latch block |28, the lever I|4 is swung by the spring |24 toits final position ||4B determined by the screw |26, and in this final lever position, the cam portions ||5 and ||8 hold both" pawls |02, |03 out of ratchet wheel feeding positions.' The grinding feed controlling valves 24 and 25 respond to the opening of the valves 20 and 2| to selectively retract the latch pins |30 and '|3| from engagement with the latch plates |21 and |28 as will be later described.

A counting ratchet wheel |33 determines the number of oscillations of the grinding wheel i4 across the raceway Reiter the feed ofthe grinding wheel has been stopped. This ratchet wheel |33, which is rotatable on a stud carriedby the frame |01, is urged clockwise by a torsion spring |34 that is opposed by a detent |35 pivoted at |36 and provided with a latch hook |3l7 normally latched under a shoulder |38 upon ahead |40 `fastened to the upper end of a valve stem |42 projecting from a control valve |43 which controls the starting and stopping of the oscillating mechanism of the grinding machine. A pawl |44, engagement with the counting ratchet wheel |33, is pivotally supported by a stud |45 carried by the outer end 0f a link |46 whose inner end is journalled upon the stud which rotatably supports the counting ratchet wheel. A generally vertical link |47, journalled at its lower end upon the stud |45, is pivoted at its upper end to the oscillating lever |04 coaxially of the pawl |03. While the lever ||4 is in either of its positions which permits the pawls |02 and |03 to produce a grinding wheel feed, a rounded upper end |40 of the pawl |44 is engaged by the lever ||4, as shown, to hold the pawl |44 out of engagement with the ratchet wheel |33. When the lever ||4 swings to its nal position l |4B to stop the grinding wheel feed, the pawl |44 is released into engagement with the counting ratchet wheel |33. The lever |04 and and the links |46 and |47 angularly oscillate the paw] |44 to produce a step by step rotation of the counting ratchet wheel |33 uniti a trip lug |50. l on an arm |52, adjustably secured to this ratchet wheel |33 by a clamp screw in a s1ot,llfts the detent |35 from the shoulder |38 to allow the valve stem |42 to descend and stop the grinding wheel oscillating mechanism, thereby providing for a predetermined number of grinding wheel oscillations during the sparking-out of the grinding wheel. The shifting of the valve |43 to stop the grinding wheel oscillations also operates through suitable mechanism, not shown, to rotate the ratchet wheel |00 backwardly for retracting the grinding wheel I4 from the grinding zone.

A plate |54, secured to and laterally projecting from the head |40. moves vertically with the valve stem |42 and acts through a pivoted link |55 to swing a bell crank lever |56 upon a stud mounted in the frame |01. and 'an upstanding arm |51 of this lever |56 operates through a pin and slot connection to position a horizontal slide |50. The slide ls supported by a guide bracket |60 havingr a tongue extendinginto a slot |02. Pivoted at |63 to the slide |50 is a lever |54 urged clockwise by a spring |65 having one end anchored by a stud on the slide. In the illustrated position, the lever |64 is held against clockwise ymovement by a lug |66 engaging the head of a stop screw |61 adjustably secured in a lug projecting from the frame |01. The shifting of the slide |58 towards the left,` in response to a downward movement of the valve stem |42, transports the lever |04 away from the stop screw |61, and the spring |65 swings this lever clockwise to lift a lever hook |10 so that during the following movement of this slide towards the left, the lever hook |10 will latch over a pin |12 on the lever H4 which is now located in its position ||4B to prevent feeding of the grinding wheel. At the start of the next grinding operation when the operator resets the valve |43 by lifting a handle |13 that projects from the head |40, the slide |58 shifts back to the right towards its illustrated position, and the lever hook |10 Vacts through the pin |12 to shift the lever I |4 past both latch pins |30 and |3| which are now located in latching positions. Final movement of the slide |50 towards the right again engages the lug |06 against the stop screw |61 causing disengagement of the hook |10 from the pin |12 and locating the lever ||4 in its coarse feed grinding position ||4A and latched against the latch pin |30. During the upward movement of the valve stem |42 and the return of the lever ||4 to its position ||4A. the head |40 cams the detent |35 away from the ratchet wheel |33, and the torsion spring |34 returns this ratchet wheel and the triplug |50tclockwise: to theinstartingz: positions which are determined by the engagement of a ratchet wheel pin |14 against a lug |15 on the frame |01. When the valve stem |42 has been lifted to its top position, the detent |35 again drops into ratchet tooth engagement and into supporting relation for the head |40.

The grinding feed controlling valves 24 and 25 are of duplicate construction and have their corresponding parts similarly identified. The latch pins |30 and |3|, which successively release the latch plates |21 and |20 to regulate the position of the feed controlling lever ||4, are respectively mounted in the heads of pistons |16 slidable in cylinders |11 and urged by coiled springs |10 towards engagement with cylinder heads to locate the latch pins in latching positions as shown by the positions of the parts of the grinding feeding control valve 25 in Figure l. Each cylinder head |00 has a through port |8| to prevent trapping of air within the forward ends oi the cylinders and which might hinder piston movement. Rearward valve extensions |03 each contain a passage |04 whose forward end opens into the rearward end of its cylinder, the rearward ends of these passages respectively opening into vertically aligned ports and |00, these ports being provided with valve seats within the passages |04. As best illustrated in Figure "l, each port |05 has an outer end open to the atmosphere, and the lower end of each port |06 communicates with a variable sized chamber |01 located between a flexible diaphragm |08 and a wall |00, each diaphragm being sealingly clamped between the wall and a recessed cap |32 which also provides a variable sized chamber |03 beneath the diaphragm. The suction pump P is connected through piping |04 to both chambers |81, and the hoses 22 and 23 are respectively connected to the chambers |03 of the grinding feed controlling valves 24 and 25. Each of these controlling valv also has a valve member |05 provided with a stem loosely extending downwardly through-one of the ports |00 for end engagement with a wear plate |08 secured to the diaphragm. A generally cylindrical head |01 on the upper end of each valve member has at top and bottom faces which are brought into relative valving engagement with the valve seats at the ends of the ports |05 and |00 within the passage |84 and under control of the deflection of the diaphragm. Each rearward valve extension |83 has a small bleeder hole |00 communicating with both of its chambers |01 and |03, these bleeder holes being of such small diameter that after the closing of the flap valves 20 and 2| there will be a short delay. as about one second, before the pressures within the flap valve passages, hoses 22 and 20 and within both sets oi' chambers |01 and |03 are balanced at the reduced pressure produced by the pump P through the piping |04. When the same reduced pressure exists in the chambers |01, |03 at opposite sides of a diaphragm, this diaphragm is sufilciently dished to permit the valve |05 to drop to its bottom position and close the port |00 and allow atmospheric pressure from the port |05 to enter the cylinder |11 so that the spring |10 will urge the piston |15 into cylinder head engagement to present the latch pin in a yieldable latching position, as indicated by the position of the parts of the grinding feed controlling valve 25. The opening of one of the flap valves suddenly increases the pressure in one of the chambers |03 to atmospheric pressure causing an upward deflection of the diaphragm |00 which lifts the valve member |05 to its top position wherein the port |05 is closed and suction from the pump communicates through the now open port |86 with the cylinder to overcome the spring |10 and withdraw the piston so that the latch pin will be'retracted from latching position, as indicated inFigure 1 by the positions of the parts of the grinding feed controlling valve 24.

In operation, a finished race ring A is mounted on the ball type gauging head 30, and the rod 44 positions the valve lever i2 in accordance with the size of the finished raceway B. A race ring C, whose raceway R is to be automatically ground to matching relation with the raceway B. is

mounted in grinding position while the stem l5 is raised out of operative position. At this time, the stud 02 is swung away from the transfer lever i0 and both nap valves 20 and 2| are closed. The suction pump P acting through the piping |04 and the bleeder holes |00 produces a balanced reduced pressure or a partial vacuum in both hoses 22 and 23 and in each pair of chambers |01, |03 causing both valve members |05 to assume their bottom positions wherein thev ports |06 are closed and atmospheric pressure has access to both cylinders |11 through the open ports |85 so that the springs |10 shift both pistons |10 into cylinder head engagement to present the latch pins |30 and |3| in yieldable latching positions with respect to the latch plates |21 and |20. The handle |13 is lifted to reset the valve |43 in its illustrated operative position to start the grinding wheel oscillating. The upward movement of the valve stem |42 acts through the plate |54, bell crank lever |56 and associated linkage to reset the lever ||4 from its position I|4B to its position ||4A which shifts both of the oscillating pawls |02 and |03 into engagement with the ratchet wheel |00 to produce a coarse feed of the grinding wheel I4 towards and into the raceway R. The lever 9 'i3 is swung to its illustrated operative position to support the stem IB on the raceway R.

When the coarse grinding wheel feed has ground the raceway R to a size determined by the preset position of the valve lever l2, the amplified linkage B3 and 84 and the transfer lever I8, controlled by the position of the stem I8. cause the screw 27 to open the flap valve 20 admitting atmospheric pressure through the hose 22 to suddenly increase the pressure within the chamber |93 of the valve 2Q, which causes the diaphragm to lift the valve member |95 to close the port |85 and open the port |86. Suction from the pump P through the port |86 now withdraws the piston |16 causing the latch `pin |30 to disengage the latch plate |21 so that the lever lid swings to its intermediate position (illustrated in fulll lines) determined by the engagement of the latch plate |28 against the latch pin |3|, this intermediate lever position limiting the engagement of the pawls |02, |03 with4 the ratchet wheel to change the coarse grinding wheel feed to a finish grinding feed.

When this finish grinding feed has further reduced the raceway R to a size predetermined by theposition of the preset Valve lever l2, the linkage operated by the stem i6 opens the flap valve 2| which admits atmospheric pressure through the hose 23 into the chamber |93 of the valve 25 causing its valve memberr |95 to shift to its top position. The suction from the pump P through the open port |86 withdraws the piston |16 of the valve 25 to retract the latch pin |3| from engagement with the latch plate |28, and the lever ||4 swings to its position ||4B which shifts both pawls |02, |03 away from the ratchet wheel to stop the nish grinding feed. Shifting of the lever H6 to its position IMB releases the pawl |44 into oscillated feeding engagement with the counting ratchet wheel |33, and the grinding wheel' oscillation across the raceway R continues during grinding wheel sparking-out until the trip lug |50 on the preadjusted arm |52 releases the detent |35 causing the valve M3 to reverse and stop the grinding wheel oscillations. During the resetting of the valve |43 and of the lever H4, the detent |35 is lifted and the spring |34 returns the counting ratchet wheel to its starting position.

I claim: l

1. In apparatus for controlling the grinding of an article to a size determined by the size of another article, gauging mechanism responsive to the reduction in size of the article being ground, a valve operated by the gauging mechanism, fluid pressure actuated means controlled by said valve for effecting a change in the rate of grinding, mechanism responsive to the size of the other article for adjusting the operative position of said valve, and means providing for a relative adjustment betweenA the gauging mechanism and the valve to predetermine the size of the article at which said valve will be operated.

2. In apparatus for regulating the grinding to size of one of a pair of articles under control of the size of the other article, gauging mechanism responsive to the size of the article being ground, a valve operated by the gauging mechanism, fluid pressure actuated grinding controlling means controlled 'by said valve, and means controlled by the size of said other article for adjusting the control between said valve and said fluid pressure actuated means.

3. In apparatus for controlling the grinding to size of one of a pair of articles for mating regrinding controlling lation, gauging mechanism responsive to the size of the article being ground, a valve operated by the gauging mechanism, fluid pressure actuated grinding controlling means controlled by said valve to reduce the grinding operation when the article being ground is reduced to a predetermined size, a gauge for measuring the size of the other article, and gauge operated means to adjust the operative position of said valve with respect to said gauging mechanism.

4. In apparatus for regulating the grinding to size of one of a pair of articles under control of the size of the other article, gauging mechanism responsive to the reduction in size of the article being ground, a, valve operated by thegauging mechanism, fluid pressure actuated means controlled by said valve for effecting a change in the rate of grinding, a gauge for measuring the size of the other of said articles and mechanism controlled by said gauge for adjusting the operative position of said valve with respect to the gauging mechanism.

5. In apparatus for controlling the grinding of an article to a size determined by the size of another article, gauging mechanism for measuring the size of the article being ground, a i'luidl pressure actuated grinding controlling device, a

plurality of valves sequentially operated by said gauging mechanism for controlling said device, and means responsive to the size of the other article for adjusting the voperative positions of the valves with respect to the gauging mechanism.

6. In apparatus for controlling the grinding to size of an article, gauging mechanism for measuring the size of the article during grinding, a feeding mechanism for a grinding operation, means for controlling the feeding mechanism and including a feed controlling lever movable to successive positions, latches regulating said lever movement, and fluid pressure actuated mechanism controlled by said gauging mechanism for Y operating the latches in accordance with the measured size of the article.

7. In apparatus for regulating the grinding to size of one of a pair of articles under control of the size of the other article, gauging mechanism responsive to the size of the article being ground, a grinding feeding mechanism, means for controlling said feeding mechanism and including a feed controlling lever movable to succes-- sive positions, latches selectively restricting the lever movement, fluid pressure actuated mechanism controlled by said gauging mechanism for selectively withdrawing the latches from said lever restricting position when the article is ground down to predetermined sizes, and means controlled by the gauging mechanism for returning the latches to their lever restricting positions when the gauging mechanism is removed from a gauging position.

8. In apparatus for controlling the grinding to size of one of a pair of articles under control of the size of the other article, gauging mechanism for measuring the size of the article being ground, a pair of valves interconnected by a duct, one of the valves being operated by thev gauging mechanism to change the pressure within the duct, said other valve responding to a pressure change in the duct a grinding feed mechanism controlled by said other valve to effect a change in rate of grinding, and means responsive to the size of said other article and arranged to adjust the operative position of the gauging mechanism operated valve.

9. In apparatus for controlling the grinding to eiIect a reduction in rate pair oi valves interconnected by a duct, suction means for producing a less than `atmospheric pressure in the duct, one oi said valves being opened by the gaugingv mechanism to increase the pressure within the duct, said other valve responding to. an increase in pressure in the duct, a grinding reed mechanism controlled by said' other valve to eiect a reduction in rate of grinding when the article is ground toa predetermined size, and means for adjusting the opening position oi said ilrst mentioned valve with respect to the gauging mechanism.

10. In apparatus for controlling the grinding to size of one o! a pair ci articles for mating relation, gauging mechanism 'for measuring the size of the article being ground, a pair oi valves interconnected by a duct, one of said valves being operated by the gauging mechanism to change the pressure within the duct, said other valve responding to a pressure change in the duct to of grinding when the article being ground is reduced to a predetermined size, a gauge for measuring the size of the other oi' said articles, and means operated by said gauge for adjusting the position oi! the gauging mechanism operated valve with respect to said gauging mechanism to control the size to which the article is ground.

11. In apparatus for controlling the grinding to size of one of a pair of articles for mating relation, gauging mechanism for measuring the size of the article being ground, a pair of valves arranged to be successively operated by the gauging mechanism when the article is respectively reduced to predetermined sizes, a gauge for measuring the size oi the other of said articles, means responsive to said gauge to adjust the operating positions oi said valves with respect to the gauging mechanism, and iiuid pressure controlled grinding feed mechanism responsive to the operation oi said valves.

12. In apparatus for controlling the grinding to size of an article, gauging mechanism for measuring the size of said article during grinding, a pair of valves arranged to be successively operated by the gauging mechanism, a pair oi grinding feed controlling valves respectively connected by ducts to said rst mentioned valves, said grinding feed controlling valves being respectively operated by fluid pressure changes in the ducts caused by the operation of .the iirst mentioned valves, and means to adjust the operating positions of said first mentioned valves with respect to said gauging mechanism.

13. In apparatus for size ot an article, gauging mechanism for measuring the size of said article during grinding, a pair of valves arranged to be successively opened by the gauging mechanism in response 'to the reduction in size o! the article, means to adjust the opening positions of said valves with respect to the gauging mechanism, a pair of grinding feed controlling valves respectively connected by ducts to said ilrst mentioned valves and operated by :huid pressure changes in the ducts caused by the opening of said first mentioned valves, and mechanism responsive to one of the feed controlling valves for reducing a grinding feed when the article is ground to a predetermined size and for further reducing the grinding' feed when the article is reduced to another predetermined size.

14. In apparatus for controlling the grinding to size oi an article, gauging mechanism for controlling the grinding to measuring the size of the article during grinding. a sell-closing valve connected by a duct to a grinding feed controlling valve, mechanism for reducing the pressure within the duct to less than atmospheric pressure when said self-closing valve is closed, the gauging mechanism being arranged to open the self-closing valve and increase the pressure within the duct when the article is ground down to a desired size, means to adjust the opening position of the self-closing valve with respect to the gauging mechanism. and means responsive to said grinding feed controlling valve for reducing a grinding feed when the pressure within the duct is increased.

15. In apparatus for controlling the grinding to' size of an article, a gauging mechanism ior measuring the size oi the article during grinding, a grinding ieed controlling valve having a pair of chambers, a member separating said chambers and moved by an unbalancing of pressures in said chambers, pressure controlling means for producing balanced pressures in said chambers, mechanism responsive to the movement oi said member for reducing the rate of a grinding feed, and means actuated by the gauging mechanism for changing the pressure in one oi said chambers when the article has been groundto a predetermined size.

`16. In apparatus for controlling the grinding to size of an article, a gauging mechanism for measuring the size of the article during grinding, a grinding feed controlling valve having a pair o! chambers, a member separating said chambers and movable in response to an unbalancing of pressures in said chambers, suction means for producing in said chambers substantially balanced pressures which are less than atmospheric pressure, mechanism responsivetc the movement of said member for reducing the rate of grinding,

and a valve operated by the gauging mechanism to unbalance the pressures in said chambers when the article is ground to a predetermined size.

1'1'. In apparatus for controlling the grinding to size of an article, a gauging mechanism for measuring the size of the article during grinding,

a grinding feed controlling valve having a pair oi chambers, a diaphragm movable under control oi an unbalancing of pressures in said chambers, means for producing in said chambers substantially balanced pressures which are less than at-A mospheric pressure, mechanism controlled by the movement of said diaphragm for reducing the rate of grinding, a valve opened by the gauging mechanism to increase the pressure in one of said chambers when the article is ground to a predetermined size, and means to adjust the opening position of said valve with respect to the gauging mechanism.

18. In apparatus for controlling the grinding to size of an article. a gauging mechanism for measuring the size of the article during grinding, a grinding feed controlling valve having a pair of chambers, a member separating said chambers and movable in response to an unbalancing of pressures in said chambers. mechanism responsive to the movement o! said member for reducing the rate of grinding, said valve having a small passage between the chambers, suction means connected to one oi said ychambers and acting through said passage to produce in both chambers balanced pressures of less than atmospheric pressure, and a valve opened by the gauging mechanism to admit atmospheric pressure into the other of said chambers for unbalancing said pressures when the article is predetermined size.

19. In apparatus for controlling the grinding to size of an article, a gauging mechanism for measuring the size ofthe article during grinding, a grinding feed controlling valve having a pair of chambers, a diaphragm separating said chambers and movable in response to an unbalancing of pressures in said chambers, mechanism controlled by a movement of said-diaphragm forreground to a .ducing the rate of grinding, said valve having a measuring the size of said article during grinding,

a grinding feed controlling valve having a pair of chambers, a diaphragm separating said chambers and movable in response to an unbalancing of pressures in said chambers, suction means for producing substantially balanced pressures in said chambers, means responsive to said gauging mechanism for unbalancing said pressures when the article is ground to a predetermined size, iluid pressure actuated mechanism for controlling a grinding feed, said valve having a passage communicating between one offsaid chambers and the uid pressure actuated mechanism, and a valve member operated by the diaphragm for opening and closing communication between said last mentioned chamber and said passage.

21. In apparatus for controlling the grinding to size of an article, a gauging mechanism for measuring the size of the article during grinding, a grinding feed controlling valve having a pair of chambers separated by a diaphragm movable in response to an unbalancing of pressuresv in said chambers, suction means for producing in said chambers balanced pressures which are less than atmospheric pressure, a device responsive to the gauging mechanism for unbalancing the pressures in said chambers when the article is ground to a predetermined size, fluid pressure actuated mechanism for controlling a-grinding feed and communicating with a passage in the grinding feed controlling valve, 'said valve having a pair of ports respectively opening said passage to the atmosphere and connecting the passage to one of said chambers, and a valve member operated by said diaphragm for selectively closing said ports.

22. In apparatus for controllingthe grinding to size of an article, a gauging mechanism for measuring the size of the varticle during grinding, a grinding feed cont-rolling valve having a pair of chambers, a diaphragm separating said chambers and movable in response to an unbalancing of pressures in said chambers, a suction pump arranged to produce less than atmospheric and substantially balanced pressures in both of said chambers, a cylinder, a piston movable in said cylinder for controlling a grinding feed, said valve having a passage communicating between one of said chambers and said cylinder, a valve member operated by said diaphragm for opening and closing communication between said last pressure controlling means and said measuring the size of the article during grinding, a `grinding feed controlling rvalve having a pair of chambers, a diaphragm separating said chambers and movable in response to an unbalancing of pressures in said chambers, said valve having a ,small passage between the chambers,

suction means connected -to one of said chambers and acting .through said passage to produce in both chambers balanced pressures of less than atmospheric pressure, a cylinder, a. piston normally urged to one end of the cylinder and moved within the cylinder in response to a change in pressure within the cylinder for reducing a grinding feed, said valve having a passage communieating with the cylinder, the valve also having a pair of ports respectively communicating from said passage to the atmosphere and to one of said chambers, a valve'inember normally closing communica-tion between the passage and said last mentioned chamber, said valve being moved by the diaphragm to selectively close said ports, and a gauging mechanism operated valve for admitting atmospheric pressure into one of said chambers to cause a. diaphragm movement.

24. In apparatus for regulating lthe grinding to size of one of a pair of articles for mating relation, gauging mechanism forl measuring .the size of the article being ground, a grinding feed controlling valve having a pair of chambers separa-ted by a diaphragm which is moved by an unbalancing of pressures Within said chambers, means responsive to the movement of the diaphragm for reducing the grinding feed, the grinding feed controlling valve having a small passage communicating between said chambers, a self closing valve connected by a duct to one of said chambers, suction means connected yto said other chamber and acting -through the passage to produce substantially equal and less than atmospheric pressures in both of said chambers, gauging mechanism operated means for opening the self closing valve to increase ,the pressure in said iirst mentioned chamber when the article is ground tothe desired size, a gauge for measuring the size of the other article, andgauge operated means for controlling the opening position of the self closing valve with respect to said gauging mechanism.

25. In apparatus for regulating the grinding to size of one of a pair of articles under control of the size of .the other article, gauging mechanism for measuring the size of the article being y ground, uid pressure controlling means operated bythe gauging mechanism, grinding feed regulating mechanism responsive to the uid pressure controlling means, and mechanism for measuring the size of said other article and arranged to adjust the operative relation between .the iluid grinding feed regulating mechanism.

26. In apparatus for regulating the grinding to size of one of a pair of articles under control of the size of the other article, gauging mechanism lresponsive to the size of the article being ground, fluid pressure controlling means regulated by the gauging mechanism, grinding feed regulating mechanism responsive to said fluid pressure controlling means, mechanism for measuring the size of the other article and arranged 15 to adjust the operative relation between the nuid pressure controlling meen; and the grinding feed regulating mechanism, and means providing for a relative adjustment between said gauging mechmism and the grinding feed regulating mecha- 5 nlsm.

WILLIAM H. BLEYSSING.

REFERENCES CITED The following references are of record in the tile of this patent: v

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